The present invention relates to a weatherstrip to be attached to the periphery of an automobile door and, particularly, to a weatherstrip 10 having a die-forming portion to be attached to corner portions A and B of an automobile door as shown in FIG. 1 and a method for molding the same.
FIG. 2 shows an example of a weatherstrip to be attached to a roof portion on the periphery of an automobile door, which comprises a hollow main body 3 to be attached still to an outer peripheral end face 2a of a doorframe with a clip or a double-sided adhesive tape, a hollow sealing portion 4 which press-contacts with a door opening margin of a car body for sealing when the door is closed, and a lip 5 protruding on an outer peripheral limb 2b of the doorframe, wherein by extending the lip 5 to the doorframe end on the center pillar side, external appearance of a corner portion at the center pillar upper end where a die-forming portion is attached is improved.
When such a die-forming portion to be attached to a corner portion is molded, the end portion of an extruded weatherstrip 6 is cut out by a fixed length from the end excluding the lip 5, then an extension 5a of the lip 5 protruding from the main body 3 is set on a metal mold, and a die-forming portion 7 as shown in FIG. 4 is molded by die forming. In the drawing, reference numeral 8 denotes a sealing portion to be connected to the sealing portion 4, and reference numeral 9 denotes a shielding portion which is die-formed for an improvement in external appearance of the end face.
When the aforementioned die-forming portion 7 is molded, the extension 5a of the lip 5 set on the metal mold easily moves and shifts in the lateral direction due to a molding pressure and, therefore, does not stay at a predetermined position. As a result, a problem in external appearance such that the lip line is curved in a molded product easily occurs. Such a problem occurs more easily as a depressing pressure by the mold becomes smaller.
The present invention is made to solve the above problem and it is an object thereof to provide a weatherstrip and a method for molding the same wherein when a sealing portion of the weatherstrip is cut out by a fixed length from the end and a die-forming portion is molded with the remaining part including a lip set on a metal mold, the part including the lip set on the metal mold is prevented from moving due to a molding pressure, whereby a problem in external appearance caused by a movement and a bend of the lip due to a molding pressure can be eliminated.
A weatherstrip according to the present invention comprises a general portion which is extrusion-molded and to be attached to a roof portion of a doorframe and a die-forming portion which is integrally molded with this general portion and to be attached to a corner portion.
The general portion has a hollow sealing portion which press-contacts with a door opening margin of a car body for sealing when the door is closed and a lip protruding on an outer peripheral limb of a doorframe, and a die-forming portion which is integrally molded with an extension of a part including the lip of the general portion and is to be attached to a corner portion, and this die-forming portion has an extension which is integrally molded with an extension of a part of the general portion including the lip portion and laterally extends to the doorframe end and a sealing portion which is integrated with the sealing portion of the general portion and has a shape along the corner portion. Moreover, position restricting means to the metal mold composed of concave portions and/or convex portions are provided on the extension of the part including the lip.
According to the present invention, when an extension of a part of an extruded molding including a lip is set on a metal mold and die forming is carried out, concave portions and/or convex portions of the extension are latched with convex portions and/or concave portions of the metal mold, whereby the position is restricted and a contact area with the metal mold is increased, resulting in an increase in frictional resistance. Therefore, the extension of the part including the lip is prevented from moving not only in a direction perpendicular to the longitudinal direction but also in the longitudinal direction, thus it becomes possible to make the extension stay at a predetermined position.
The position restricting means of the present invention restrict movement in the direction perpendicular to the longitudinal direction of the extension set on the metal mold as mentioned above, however, it is desirable that such a restriction in movement is imposed not only in the right and left direction but also in the up-and-down direction. Therefore, it is desirable that the concave portions and/or convex portions are formed not only in the up-and-down direction but also in the lateral direction.
In a method for molding a weatherstrip according to the present invention, the end portion of an extruded molding having a hollow sealing portion, a lip protruding on an outer peripheral limb of a doorframe, and position restriction means to a metal mold composed of concave portions and/or convex portions is cut out by a fixed length from the end excluding a part including the lip and position restricting means. Thereafter, the part remaining including the lip and position restricting means after cutting is attached and set on a metal mold by latching the concave portions and/or convex portions of the position restricting means with convex portions and/or concave portions of the metal mold. Then, a die-forming portion is molded by injecting a molding material of, for example, ethylene-propylene diene rubber (EPDM) into the metal mold.